Electric switch



Dec. 7, 1954 A. BROWN ErAL ELECTRIC SWITCH 6 Sheets-Sheet l Filed Jan.8, 1949 fl T TOF'NEY Dec. 7, 1954 A. BROWN ETAL 2,696,553

` ELECTRIC SWITCH Filed Jan. 8, 1949 6 sheets-sheet 2 @WMV /QL Dec. 7,1954 A, BROWN ETAL 2,695,553

ELECTRIC SWITCH Filed Jan. 8, 1949 e sheets-sheet s ATTORNEY' De- 7,1954 A. BROWN ETAL 2,696,553

ELECTRIC SWITCH Filed Jan. 8, 1949 6 Sheets-Sheet 4 TTOZP/VEY Dec. 7,1954 A, BROWN ErAL ELECTRIC SWITCH 6 Sheets-Sheet 5 Filed Jan. 8, 1949 UWkOQ.

l Y WKDQQ Dec. 7, 1954 A. BROWN rs1-AL 2,696,553

ELECTRIC SWITCH Filed Jan. 8, 1949 6 Sheets-Sheet 6 v Q Q Q QJ Lk O fn2' N F/G/Oa. F/G/Oc. 42 42 g LD' l l INVENTORS A TTOFNEY United StatesPatent C ELECTRIC SWITCH yAndrew Brown and Denis Alexander Tomlin,London,

Application January 8, 1949, Serial No. 69,882

Claimsvpriority, application Great Britain January 22, 1948 1 Claim.(Cl. 246-434) The invention is concerned with electrical switches.

The main feature of the invention is an electric switch comprising anumber of contact sets and means for selecting and operating any one orany combination of the contact sets, wherein selection of a contact setor sets to be operated is carried out without disturbance of any contactset.

One possible application of this type of switch is for use in railwaysignal and/or points control systems of the kind using multi-positionmotor-driven rotary control switches for controlling the selection andsetting up of any one of a number of diierent routes outgoing from aparticular position as described in the U. S. Patent 2,241,906 which wasvissued on May 13, 1'941. Such systems require less apparatus thanalternative relay systems and each switch can accommodate manycontactsand can be used for a number of routes equal tothe number of positionsto which it can be set.-v This has been done by having a rotor, carryinga number of cams, being arranged to stop 1n a number of differentangular positions. These different positions are allocated to -ditcrentroutes, and the cams are cut to give the desiredcontact arrangement ineach position. The routes which conflict with one another are allocatedto positions on the same switch and interlocking between them isVautomatic, since the. rotor can be in only one position' at ay time.However, conflict between routes on different switches cannot usually beavoided. Previous. switches of the kind described have had certaindisadvantages. In passing from the home or normal position of the rotorto say position 5, positions 1-4 must be passedl through. Thesepositions may have been: allocated to routes which conllict with routesalready setup on other switches. Prod vision. has therefore had to bemade so that when the first switch passes through these conicting routepositions it does not break down the routesf set upl on the otherswitches. A-t ther same time itl has had to be arranged that if, by somefault, the first switch should stop in any of these conflicting routepositions, noy dangerous condition will arise. Further disadvantageshavebeen, (1) that a switch could stop by fault between two route positions,(2) the rotor assembly has had to belv specially made for everyparticular switch, and (3,) that a change in a circuit or interlockingrequired the removal of the switch rotor and alteration in the'. cuttingof the cams.

A switch, according to the present invention, while achieving. theeconomy of spaceY and contacts. of the motor-driven. multi-positionswitches', has none'- of: the above disadvantages when used in. railway'signalling systems. g

The invention will be particularly described in relationk to twoembodiments thereof shown in theaccompanying drawings, in which:

Fig. 1 showsV an elevation, part sectionedf, ofva switch according tothe first embodiment;

Fig. 2 shows a diagrammatic elevation of the switchy shown. in Fig. 1from a viewpoint' at ,right angles t'o thatused for Fig. 1;

Fig. 3 shows schematicallyv circuits for the driving andpositioningcamsA of the switchshown; inthe previous two figures; l

E ig.. 4v is: a diagrammatic elevation' of a switchv according to. the.second embo'dimentlof thel invention;

Fig.. 51? illustrates diagrammatieally the methodn adoptedE 2,6 6,553ice 9 Patented Dec. 7, 1954 2 in this second embodiment for ensuring theengagement of one of the Code bars with the contact sets, whilst` Fig. 6shows in some detail, part of the operating method outlined in Fig. 5,this view being of a limited nature, only three selecting bars and onecfode bar being included;

Fig. 7 is a section on the line X--X of Fig. 6;

Fig. 8 shows in schematic form the circuit arrangements for the switchforming the subject of Figs'.` 4-7,

Fig. 9 shows a diagrammatic elevation of a modified switch of the samegeneral kind as shown in Fig. 4, Whilst Figs. 10A to 10D show dilierentpositions which may be taken up by a latch forming an important 'part ofthis modified switch.

The general operating arrangements of the switches according to threeembodiments of the invention will now b e described. In the tir'st, themotor-driven rotor of prior art switches as shown for instance in U. S.Patent No. 2,260,292 is retained, but instead of cams, it has a rotor,around which are attached a number of code bars extending parallel tothe axis of the' rotor and spaced around the periphery thereof, eachhaving a distinctive cut in the free end thereof. The code bars are soplaced that in each of the route positions one of the bars can engagewith a predetermined number of contact sets in accordance with thedistinctive cut in the ends of the code bars. A prime mover and cams areassociated with the rotor to drive it into and prove its position. Thishaving been proved, a solenoid, motor-driven cam or other' elecitrically operated mechanism causes relative movement between the rotorand the contact sets.- Acco'rding toV how the code bar is cut, apredetermined selection of these contact sets is operated. Therefore,any4 desired contact' set or combination of contact sets may be operatedin each of the route positions,

The code bars are made easily detachable so that eachcan be removed andits cutting altered without interfering with the use of the switch inthe remainder of its route positions. Since the solenoid or othermechanism is not operated untill the rotor .is in the exact positiondesired, passing through other route positions hasl no effect on thecontacts, and can be ignored from an inter; locking point of view.

In the second form of the switch, no rotor is used and the code bars arein parallel slides. They are individually selected by electromagnets,and lifted to operate the contacts by solenoids, motor-driven cams, orother means'. This second arrangement has the advantage of being quickeroperating than the first switch utilizingthe rotor.-

In Figs. 1 and 2 aswitch of the rotor type is shownV with its rotor 1mounted on a shaft 1A together with 7 double-sided cams 2- 8l along withone part 9A of a magnetic clutch indicated generally at 9'. The shaftl-A is rotatably mounted in twobearings 10, said bearings being carriedon pivoted arms 11 joined together toform the armature cooperating withay magnet 1-2'-, In Fig. 2 the rotor is shown as' having sixpcode bars13, one of them being immediately' beneath the insulating studs 14I ofthe Contact sets 1'5. When the magnet 12in energized, the rotor israised and the-uppermost code bar 1'3 is brought into `engagement" withthe" insulated studs of certain of the contact sets. Where the code barhas` been cut away the insulated studi 14 is not contacted and contacts15 remain unoperated, but where the code bar' has been left the contactsare operated. This is clearly shown in` Fig'. l.

If it is desired to operate the route allocated to position A of therotor, the circuit' is ma'de over the contacts` of the route switchl andother appropriatey switches- (not shown) to prove that no' coniiictingroute has been' set up and from thereto thevwipersof cams 3l and 6simultaneously. The cams 2. 8f consist of suitably cut discs' 2e', 2f8e, 8f of copper or bronze rivetted to'insulatedy discs 2b 8b,r'espectively'as-shown inx Fig. l. Thecam surfaces'e and f thereforeform one unit 6 in` electrical contact with eachother. AA contact ismade between the three camy units 6- and 6a, 7- andv 7a, 8i and 8a, bymeans* of' metallic rin'gsl1'6 between them; Separate wipers 2c', 2d,3c, 311,746, 4d, 5e, 6c, 6d, 7c,7d, are provided for' correspondingcams. Anladditionallwiper 17 istil-evicted to complete the circuit torelay ZR. If the cani 6 is in the position shown in Fig. 3, whichposition corresponds to route A, it will be seen that a circuit is madefor relay ZR via battery, winding of relay ZR, wiper 17, metallic ring16, contact surface of cam 16, wiper 6c, lead A, route allocationselector switch (not shown), positive battery. Relay ZR having operated,the clutch coil 9 is energized over positive battery zr1 front coil 9,to negative battery (Fig. 3). When the clutch is energised it attractsto it a clutch armature plate 18, which is held by a spring spider 19connected to part 9a on the rotor shaft. The main shaft is driven by anelectric motor (not shown), and drives the magnet coil portion 9b of theclutch through gears 21. The main drive motor may be either continuouslyrunning or started by the operation of a contact (not shown) controlledby the ZR relay. When the clutch armature plate 18 is attracted by theenergised rotating magnet coil, friction between surfaces is suicient todrive the rotor. This continues until position A is reached, when thecircuit for relay ZR is broken by the insulating segment on cam 6 asshown in Fig. 3. The cam 2 is used to continue the drive after relay ZRis released, until the rotor is accurately positioned. When the clutchcoil 9b is deenergised the armature 18 is released, and the drive to therotor is broken, so that the rotor stops in position A. With the rotorin this position a circuit is made for relay ZCR over cam 3, as shown inFig. 3, and the relay is operated via negative battery, winding ofrelays zcr, wiper 17a, negative battery, contact surface of cam 3, wiper3c, lead A, route selecting switch (not shown), positive battery. Cams3/5 are assembled similarly to the cams 6/ 8. When relay ZCR is operateda circuit is provided for the contact operating magnet 12 via: positivebattery, contact zcrl; winding of magnet 12, negative battery, causingthe magnet 12 to attract its armature, and in so doing to lift the wholerotor 1. When the rotor is lifted the code bar 13 is engaged with theinsulated studs 14 of the contact sets, thus operating a particularcombination of the sets. All the contact sets shown are make contacts,but break or changeover contacts can be used when required.

A switch constructed according to the second embodiment of theinvention, the parallel slide-bar type is the subject of Figs. 4-8, Fig.4 showing an assembly of selecting and code bars. Resting along the topof the code bars 13 are the contact levers 22, which operate the contactsets 15. The lifting arms 23 are raised by cams or eccentrics (as at 24)and are pivotted so that their motion is parallel to that of the contactlevers 22. The

code bars 13 and the selecting bars 25 are assembled together withseparating guides 26 in a box (see Fig. 7), so that the selecting bars25 can be moved longitudinally in a direction normal to the plane of thepaper and vertically and the code bars 13 vertically only. The liftingof a selecting bar raises its associated code bar. The sets of code andselecting bars are separated by the thin sheet-metal guides 26 which areanchored so that they only have a small amount of side-play.

When a selecting bar has been operated, that is, moved longitudinally,its engaging detents 27 become positioned above the lifting arms 23(Fig. 5), so that the raising of the lifting arms raises the selectingbar and its associated code bar. The selecting bars which are notoperated have their clearing detents 28 above the lifting arm, so thatthe raising of the arm does not aect them.

Since the lifting arms 23 Vand the contact levers 22 are parallel, thelatter are lifted by the same amount, no matter which pair of selectingand code bars acts as the link between them.

Fig. 6 shows in greater detail the method of operating the selectingbars. The selecting bars each have cut away from them a number ofsimilar notches 29. The notches except for one different one of eachbar, are equally spaced. This different notch in each case is displacedto the right, and no bar has the notch in the same position displaced. Aswitch to handle l2 routes will therefore require 12, 12-notch selectingbars, and 12 code bars. Cams 30 are engaged with the notches so thatwhen a cam is turned through 90 all the notches in that position arebrought into line as shown at the central notch in the figure. Thisbrings all except one of the selecting bars into the unoperatedposition. The selecting bar that has a displaced notch in that positionis however moved to the left as is indicated by dotted lines, so thatits engaging detents 27 are above the lifting arms 23.

Each selecting cam is operated by its own electro magnet 31, 32, 33through cooperating armatures 31a 33a to which are coupled linkagelevers 31b 33b, respectively.

The stop arm 34 prevents any selecting bar from being lifted unless itis in the operated position; a bar in the operated position allows thestop arm to drop into a cooperating slot 35 adjacent one end ofselecting bar 25, which slot is provided for the purpose.

Electrical contact cams are provided on the same shaft as the liftingcams or eccentrics but are not shown in the drawing. These cams aresimilar to those described for the rst embodiment. Some are used todrive and position the lifting cams, while others are used to isolatethe selecting magnets when the lifting cams are operated. In Fig. 8 onlythere are indicated the contacts which are required to close when theselecting cams are operated.

If it is desired to operate route A (see Fig. 8) a circuit is providedfrom the route key via the contacts of other interlocking switches tocam C of the interlocking switch, and by a contact made in the normalposition to the selecting magnet SMA. This operates the associatedselecting bar via the selecting cam, and locks the remainder of the barsin the unoperated position, in the manner as has already been describedand shown in Figs. 6 and 7. The contact of the selecting cam smal frontextends the circuit already provided for cam D, to cam G, which, in thenormal position, connects to the clutch coil Z, which is energised overan obvious circuit.

This clutch, which may be similar to that described for the firstembodiment, drives the lifting and selecting cams. Immediately the camsleave the normal or unoperated position, the circuit for the selectingmagnet is broken at cam D, and to the clutch coil Z by the contact smaland cam G. The clutch remains energised however, over cam H which .iscut to be disconnected in both the normal and reverse positions, andconnected in inter mediate positions. Therefore the drive is continueduntil the reverse position is reached, when the circuit for the clutchis broken, and the cams stop, the selecting bar cam having been turnedthrough The lifting arms having been raised, the contact sets requiredfor route A are operated. One of these contacts, acl (which is onlyoperated in that route position) extends the original circuit from cam D(now in the reverse position), to relay ZCR, which operates and provesthat the switch is in the desired route position.

When it is desired to break down the route, the original circuit isbroken, and relay ZCR is released. This will effect the route signalsbeing changed to red, but will not release the route contact selection.When it is considered safe to break down this selection the releasecircuit for route A is made, which over a02 front energises the ZNRrelay. Over znr2 front the clutch coil is energised over the reversecontact of cam G. The cams are thereafter driven until they are in thenormal position, when the circuit for relay ZNR is broken, and theclutch is de-energised.

Where a route requires a larger number of contact sets than are normallyavailable on one switch, there may be attached to it one or moreextension units. These units will have code bars, Contact levers, andcontact sets similar to the main switch, but the code bars will belifted by means of push rods 35 interposed over the code bars of themain switch as shown in Fig. 6. The extension units will therefore bemounted in layers above the main switch.

In order to guard against the possible false contact due to failure orbreakage of studs on the contact springs, contact sets required to benormally closed are mounted below the contact lever, or equivalentcontact spring, and held there by the initial tension on the contactlever. In this case, the breakage of any operating stud has the effectof opening rather than closing the contact.

In the rst embodiment, as well as in the second, a motor-driven cam canbe used to lift the code bar assembly (e. g. the rotor). This motor maybe an individual drive motor or, common motor driving a cam throughclutches as pointed out previously in connection with the description ofFig. l. Other variations possible include the use of self-latchingarmatures with specialrelease arrangements.

In a third embodiment, it is proposed to incorporate in a standardarrangement two sets of contacts, one operated as beforev when theliftingarms 23 are raised whilst the other set requires for itsoperation that the arms 23 shall be lowered. This scheme is showngenerally in Fig. 9 and it will be seen that an cectromagnet 37 isincluded in place of the eccentric lifting device 24 indicated in Fig.4. There are shown the usual code bars 13, selecting bars 25 and contactlevers 22, but the latter is arranged not only to actuate an uppercontact set 15, but also a lower set 38. The lifting arms 23 co-operate,at the end away from the electromagnet 37, with a latch 39 which has astepped slot. An end elevation of this latch is shown in Fig. 10A,wherein the slot 40 can be clearly seen, whilst Figs. 10B, 10C and 10Dwill help in an understanding of the operation of this device.

As before the arms 23 ou being lifted operate the make-contact sets 15so arranging the setting up of the required route, The normal relativepositions of the arm 23 and the latch 39 are shown in Fig. 10A, it beingunderstood that the latch is pivotted about the spindle 41. The arm 23on being raised knocks against the surface 42 of the slot 40 so that asseen in Fig. 10B, the latch is displaced clockwise about its pivot 41.When the control switch of the route is released, the signals arearranged to go to danger immediately the upper contact set 15 is broken,but the arrangement is designed to ensure that no further routeinvolving the contacts which have just been operated can be set up onany switch until a well-known back-lock has freed them for furtherservice.

This desired result is achieved as follows: The magnet 37 releases thearms 23 but the fall is checked by the step 43 in the latch slot 40.This condition is shown in Fig. 10C. When the setting up of furtherroutes is permissible the back-lock controls the quick operation ofelectromagnet 44. This attracts an armature extension 45 of the latchand as will be seen from Fig. 10D,

the latch 39 is rotated counter-clockwise and the arm 23 is releasedfrom the step 43 and drops down in normal position so that the contacts38 are remade. The magnet 44 soon afterwards releases and the latch 39returns to its normal vertical position shown in Fig. 10A. The

circuit arrangements are such that elements of the route which has beenbroken down may now be used in the setting up of the routes.

While the principles of the invention have been described above inconnection with specific embodiments, and particular modificationsthereof, it is to be clearly understood that this description is madeonly by way of example and not as a limitation on the scope of theinvention.

What is claimed is:

An electric switch comprising a plurality of code bars operable toengage through contact levers with a rst plurality of contact sets, anybars being operable to effect the operation of one or more of the saidcontact sets, a plurality of selecting bars one for each of the saidcode bars, means which engage notches in the said selecting barsoperable to effect movement in a first plane of any one selecting bar ata time and a pivotted lever operable to be displaced after said movementhas taken place so as to engage with the said particular selecting bar,displacing the latter and its associated code bar in a second plane thusoperating the appropriate contact set or sets via their contact levers.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,873,729 Wheelock Aug. 23, 1932 1,969,978 Hanel Aug. 14, 19342,116,731 Noll May 10, 1938 2,241,906 Grths et al May 13, 1941 2,248,704Griffiths et al July 8, 1941 2,260,292 Brown et al. Oct. 28, 19412,323,824 Maschmeyer July 6, 1943 2,361,246 Stibitz Oct. 24, 19442,364,446 Hubbard Dec. 5, 1944 2,480,945 Marmony Sept. 6, 1949

